(1) Field of the Invention
The present invention relates to a device for selecting print characters of endless printing bands in a printer, particularly a device for selecting print character of endless printing bands in a printer mounted in a portable printing and labeling device (hand labler).
(2) Background Art
In a conventional hand labeler or the like, print characters and display characters are formed on endless printing bands, these are rotated to put desired print characters in a printable state, ink is applied to the print characters by an ink roller or the like, and a label or the like is stamped.
However, when an endless printing band is made rotatable within an arbitrary rotation range, the display characters come opposite the ink roller and are fouled by application of ink.
For overcoming this problem, there is, as set out for example in Japanese Patent Application Laid-open No. Hei 10(1998)-44575, a device for preventing fouling of display characters in a printer wherein slack is produced in endless printing bands provided between selector wheels and a print character bearing base section (print pressure bearing section or print pressure bearing member) to enable idle rotation of the selector wheel. Although this device for preventing fouling of display characters in a printer prevents fouling of the display characters while enabling maintenance of endless printing band durability, it has a problem in that it is sometimes difficult to realize alignment in the print character selection operation at the print character bearing base section (proper setting state of individual print characters with respect to the print character bearing base section or distinction between set states).
Moreover, since the print character bearing base section is fixed, it receives the print pressure through the endless printing band and damage of the print character bearing base section by the impact force is therefore a problem.
Despite the fact that it may be desirable to increase the number of kinds of print characters in order to print more kinds of information, print characters can be formed on substantially only half the endless printing band peripheries when a structure is provided for preventing fouling of display characters. In the case where a conventional device for preventing fouling of display characters is provided, therefore, endless printing bands having print characters on most of their peripheries cannot be installed. This gives rise to the problem of not being able to support full-periphery printing.
In other words, no device for selecting print characters of endless printing bands has enabled selective adoption or combination of full-periphery printing capability permitting printing of many kinds of information owing to the formation of print characters over the entire periphery of endless printing bands and half-periphery printing capability permitting prevention of display character fouling but allowing printing over only half the peripheries so as to enable printing of desired amounts of information with a desired number of print characters and also, when necessary, enable prevention of display character fouling.